Tuesday, January 23, 2018

android kotlin - If else example

MainActivity.kt 

package com.cfsuman.kotlinexamples

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.Button
import android.widget.TextView


class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Get the widgets reference from xml layout
        val textView = findViewById<TextView>(R.id.text_view)
        val button = findViewById<Button>(R.id.button);
        val button2 = findViewById<Button>(R.id.button2);
        val button3 = findViewById<Button>(R.id.button3);
        val button4 = findViewById<Button>(R.id.button4);

        // Initialize some integer type variables
        var a:Int = 5
        var b:Int = 10
        var c:Int = 8

        // Traditional if statement
        button.setOnClickListener{
            var max = a

            if(a < b) max = b
            textView.text = "From $a and $b, biggest number is $max"
        }


        // If with else statement
        button2.setOnClickListener{
            var max:Int

            if(a > b){
                max = a
                textView.text = "$max is biggest number in $a and $b"
            }else{
                max = b
                textView.text = "$max is biggest number in $a and $b"
            }
        }


        // If else if statement
        button3.setOnClickListener{
            var max:Int

            if(a > b && a > c){
                max = a
                textView.text = "$max is biggest number from $a and $b and $c"
            }else if (b > a && b > c){
                max = b
                textView.text = "$max is biggest number from $a and $b and $c"
            }else{
                max = c
                textView.text = "$max is biggest number from $a and $b and $c"
            }
        }


        // If as expression
        button4.setOnClickListener{
            // If else in one line
            var max = if(a > b) a else b
            textView.text = "$max is biggest number from $a and $b"
        }
    }
}
activity_main.xml 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/root_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp"
    >
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="If Statement"
        />
    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="If Else Statement"
        />
    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="If Else If Statement"
        />
    <Button
        android:id="@+id/button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="If As Expression"
        />
    <TextView
        android:id="@+id/text_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text=""
        android:textSize="23sp"
        android:textStyle="bold"
        android:textColor="#ff191d"
        android:layout_marginTop="20dp"
        />
</LinearLayout>
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